There are some plot similarities between these two 80s sequels. Both are about families moving into a house with a haunted history that ends up possessing the teenage male of the bunch. Both guys hear voices and have sexual hang-ups too. Jesse is a closet homosexual and Sonny has incestuous feelings toward his sister. Also, the fathers are both assholes played by cool actors.

NoES2 is more of a haunted house movie than you might initially realize. Besides the gradual possession, it's always hot inside. The AC never works and birds explode. After this movie, I'm pretty sure the house was featured in at least 1 or 2 episodes of the show, but would quickly be deemed too haunted to live in and thus existed mostly as a decayed dream figment until Lori move in for FvJ. It was still never depicted strictly as a haunted house, considering Freddy's spread was never confined to just that house, but rather the titular Elm Street (and part 6 proves that bit isn't even a firm rule).

I guess I can sort of understand why Amityville 2 changed the DeFeo family to the Montellis. They wouldn't want to sympathize the actual killer and bank off a real family's misfortune, but I'm not sure the sequels ever really acknowledged the Montellis, nor Sonny's fate.

I was wondering what ever happened to Jesse after NoES2 also. He's never featured in any sequels outside of some non-canon comics, and the actor believes he's alive, but in what state? I guess that's another thing the two have in common: lack of closure. We never know what happened to these guys after their movies, despite there being a bunch of sequels after that could have mentioned something. Also, both movies are not set in the years they were made. And both movies were also written, directed by, and starring human beings, as far as I know.